For 2003 I will need to meet 99db for cross country races in Oregon, plus I want to be able to tune/change the pipe for the MX track. I want to know who is using a pipe that take cores and can add/delete discs to tune for sound and power or something similiar. Like is WB E series a good bet you can add discs and a quiet core, which amount to a good amount of flexibility, although I heard they had welds cracking, FMF claims a quiet core for the Power Core 4. Any info much appreciated. Also any one tried wraping the SA in the stock pipe with steel wool and then FMF pipe packing to bring the level down?